399971 has 8 divisors (see below), whose sum is σ = 470064. Its totient is φ = 335520.

The previous prime is 399953. The next prime is 399979. The reversal of 399971 is 179993.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 399971 - 2¹⁴ = 383587 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 399971.

It is not an unprimeable number, because it can be changed into a prime (399979) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1256 + ... + 1541.

It is an arithmetic number, because the mean of its divisors is an integer number (58758).

2³⁹⁹⁹⁷¹ is an apocalyptic number.

399971 is a deficient number, since it is larger than the sum of its proper divisors (70093).

399971 is a wasteful number, since it uses less digits than its factorization.

399971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2821.

The product of its digits is 15309, while the sum is 38.

The square root of 399971 is about 632.4326051051. The cubic root of 399971 is about 73.6788493146.

The spelling of 399971 in words is "three hundred ninety-nine thousand, nine hundred seventy-one".